Tool for picking tubular key cylinder locks



May 17, 1966 R. GRUBER 3,251,206

TOOL FOR PICKING TUBULAR KEY CYLINDER LOCKS Filed June 27, 1963 J9 IOWA? United States Patent 3,251,2ll6 TOOL FOR PICKING TUBULAR KEY CYLINDER LOCKS Robert Gruber, 3139 N. Paulina, Chicago 13, Ill. Filed June 27, 1963, Ser. No. 291,089 4 (Ilairns. (Cl. 70-694) This invention relates to locksmiths tools and refers more particularly to a picking tool for cylinder locks of the type wherein the front end portion of a cylinder that is rotatable in a casing cooperates with the casing to define an annular keyway in which a tubular key is receivable, the key having hitting on its front end that cooperates with spring biased tumblers in the lock which move parallel to its axis.

Tubular key cylinder locks, such as those sold under the trademark Ace and Gem, are frequently used on the coin boxes of vending machines and on switches that control the electrical circuits of audible burglar alarm systems. The tubular key that is accepted by a lock of this type is not as readily duplicated as the more conventional flat key intended for a cylinder lock having a slot-like key receiving aperture, and tubular key locks have the further important advantage that they cannot be picked by means of conventional picking tools.

Upon occasion, however, there are legitimate reasons for having a tubular key type of lock picked by a locksmith, who is bound by the recognized ethical standards of his profession, just as there are legitimate reasons for picking any other type of lock. With this in mind, it is a general object of the present invention to provide a locksmiths tool by means of which the picking of a tubular key type of cylinder lock can be very quickly and easily accomplished.

More specifically it is an object of the present invention to provide a tool whereby torsional force can be applied to the cylinder of a tubular key type of lock simultaneously with the application of axial force to each of the tumbler drivers of the look, so that the tumblers can be individually depressed against the bias of their respective springs until each tumbler driver and its tumbler are brought to aposition at which their adjacent ends are on the line of shear of the lock, and which tool provides for maintaining each tumbler driver in said position while other tumblers are being depressed.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof,

and in which:

FIGURE 1 is a perspective view showing a picking tool of this invention together with a cylinder lock of the tubular key type on which the tool can be used;

FIGURE v2 is a side view of the tool; and

FIGURE 3 is a front end view of the tool.

Referring now more particularly to the accompanying drawing, the numeral 5 designates generally a locksmiths tool embodying the principles of this invention and which is useful for picking a lock 6 of the tubular key type wherein the front end of a cylinder 7 that is rotatable in a casing 8 cooperates with the casing to define an annular keyway 9. Normally such a lock is intended to be locked and unlocked by means of a tubular key 3,251,206 Patented May 17, 1966 (not shown) having bitting on its front end. To provide for transmitting rotational force from the key to the lock cylinder, the latter has a groove 10 that ex tends lengthwise along its front portion and opens to its front end and to the annular keyway 9, in which groove a lug on the key engages.

The picking tool 5 of this invention comprises, in general, a plurality of long, slender fingers 11, one for each tumbler in the look to be picked, and an elongated carrier 12 on which the fingers are mounted and which comprises a cylindrical stem or body .13 and a handle 14 fixed on the rear of the stem. The fingers 11 extend lengthwise along the stem, are circumferentia'lly spaced around it to correspond with the circumferential spacing of the tumblers in the lock to be picked, and are length- Wise 'slidealble relative to the carrier and to one another. At its front the stem has a tubular portion 15 with an inside diameter to closely fit the front .pontion of the cylinder of the lock and with a wall that is thin enough to be intenpos'ed between the cylinder and the tumbler drivers. A lug 16 projects inwardly from this tubular portion for rotation transmitting engagement in the groove 10 in the cylinder.

The fingers '11 are preferably made of straight strips of tempered spring steel, having sufficient stilfness so that substantial endwise force can be applied to them Without appreciably flexing them but having enough resilience so that they will not be permanently deformed by the application of substantial bending force to them.

The stem or body portion 13 of the carrier 12 may be formed from tubular stock having an inside diameter equal to the outside diameter of the front portion of the cylinder of a lock to be picked. Compartments 17 in which the fingers are confined, and by which they are constrained to and guided in lengthwise sliding motion, are formed in the body portion of the carrier. Preferably the compartments 17 take the form of radially outwardly opening grooves in the stern, each substantially equal in width to a spring finger and defined by circumferentially spaced apart lengthwise extending lands 18 on the stem.

The fingers 11 are confined in their respective grooves by a band 19 of rubber or similar elastic material which encircles the stem and the several fingers under substantial tension. The band 19 has the further function of frictionally restraining lengthwise movement of the fingers in their compartments to the extent that each finger can move relative to the carrier only in response to exertion upon the finger of an endwise force substantially greater than that which a tumbler spring in a lock to be picked exerts upon its tumbler and driver. To insure that the band will provide the necessary frictional restraint upon the fingers, the lands 18 should have a height that is about equal to the thickness of the fingers, so that the band securely engages both the lands and the fingers.

The handle 14, which may be similar to that on an ordinary screwdriver, is coaxially and nonrotatably secured to the rear of the stem or body 13. The thinwalled tubular projection 15 on the front end of the stem may be integral therewith if the stem is made of tubular stock, and can be formed by concentrically turning down the outside diameter of the stem stock for a sufiicient axial distance from its front end to assure that the larger diameter portion of the stem will not engage any of the tumbler drivers in a lock to be picked. The lug 16 can be formed integrally with the tubular projection.

In using the tool to pick a lock, the several fingers are first moved to the positions shown in FIGURE 1, with their front ends even with the front end of the tubular projection 15 on the front of the carrier. To facilitate placement of the fingers in this position, a washer or collar 20 can be slideably mounted on the rear portion of the stem 13, just in front of the handle 14, for engagement with the rear ends of the fingers, so that all of the fingers can be pushed forward together by means of the collar. The rear ends of the lands 18 can define rearwardly facing abutments that provide a stop which terminates forward motion of the collar when it reaches a position at which the front ends of the fingers are even with the front end of the tubular projection. Alternatively the stop can be so located that the fingers can be pushed some distance beyond the front end of the tubular projection, to be returned to the desired position by pressing the tool against any convenient flat surface. If desired, the rear end portions of the fingers can be bent outwardly at right angles as at 21 to have fiatwise engagement with the front face of the collar.

In use, the tool of this invention is inserted slowly into the annular keyway 9 of a lock to be picked, with the lug 16 engaged in the groove 10 in the lock cylinder. While applying twisting force in the unlocking direction to the handle 14 of the tool, the tubular projection 15 is slowly advanced along the cylinder and at the same time the handle is swung around a small orbit. Such advancing and orbital motion of the tool causes each finger in turn to engage its tumbler driver, and because of the restraint against rearward motion of the finger which the band 19 exerts, the finger propels the tumbler driver and its associated tumbler rearwardly as the tool is advanced into the look. When a tumbler driver and its associated tumbler have been driven to positions where their adjacent ends are on the shear line of the lock, the torsional force being exerted upon the cylinder through the tool will effect a slight misalignment of the tumbler and driver bores by which the tumbler and driver are prevented from crossing the shear line. When the tool has been advanced to where all of the tumblers are retracted, the cylinder will of course rotate to its unlocked position in response to the torsional force being applied to it through the tool.

From the foregoing description taken together with the accompanying drawing it will be apparent that this invention provides a simple, inexpensive and sturdy locksmiths tool by means of which a cylinder lock of the tubular key type can be quickly and easily picked.

What is claimed as my invention is:

1. A tool for picking locks of the type wherein the front portion of a cylinder rotatable in a casing cooperates with the casing to define an annular keyway, and wherein spring biased tumblers have tumbler drivers arranged for actuation by hitting on the end of a tubular key inserted into the keyway, said pick comprising:

A. an elongated cylindrical stem having (1) a tubular end portion of a size and shape to enter the annular keyway of a tubular key type cylinder lock and to closely embrace the front portion of the cylinder, the wall of said tubular end portion being substantially thin so that it can be interposed between the tumbler drivers 7 and the cylinder, and

(2) a cylinder drive lug on said end portion of the stem, projecting from the interior thereof;

B. a handle on the other end portion of the stem;

C. tumbler actuating means carried by the stem, at its exterior, comprising a plurality of slender, elongated fingers, one for each tumbler of a lock to be picked;

D. means mounting said fingers on the stem with the fingers extending lengthwise of the stem and over said cylindrical end portion thereof and with the fingers in circumferentially spaced relationship, said mounting means constraining the fingers to rotate bodily with the stem while providing for lengthwise movement of each finger relative to the stem and to the other fingers; and

E. an elastic band embracing all of the fingers and the stem under circumferential tension and engaging the fingers and the stem to at all times frictionally restrain the fingers against lengthwise motion relative to the stem except in response to the exertion of lengthwise forces upon the fingers that are greater than those that are yieldingly imposed upon the tumblers of a cylinder lock by their springs.

2. The lock picking tool of claim 1, further characterized by the fact that said means mounting the fingers on the stem comprises: a plurality of shallow lands on the stem, extending toward the handle from a point spaced from the first designated end of the stem and cooperating to define shallow lengthwise extending grooves in which the fingers are received.

3. The lock picking tool of claim 1, further characterized by a collar slidable along the stem, between the handle and the ends of the fingers adjacent to the handle and engageable with said ends of the fingers to provide for simultaneously sliding all of the fingers along the stem to positions in which their other ends are even with the first designated end of the stem.

4. A tool for picking locks of the type wherein the front portion of a cylinder rotatable in a casing cooperates with the casing to define an annular keyway, and wherein spring biased tumblers have tumbler drivers arranged for actuation by hitting on the end of a tubular key inserted into the keyway, said pick comprising:

A. An elongated cylindrical stem having (1)' a tubular end portion of a size and shape to enter the annular keyway of a tubular key type cylinder lock and to closely embrace the front portion of the cylinder, the wall of said tubular end portion being substantially thin so that it can be interposed between the tumbler drivers and the cylinder, and

(2) a cylinder drive lug on said end portion of the stem, projecting from the interior thereof;

B. means on the other end portion of the stem providing a handle;

C. tumbler actuating means carried by the stem, at its exterior, comprising a plurailty of slender, elongated fingers, one for each tumbler of a lock to be picked;

D. means mounting said fingers on the stem, with the fingers extending lengthwise of the stem and over said cylindrical end portion thereof and with the fingers in circumferentially spaced relationship, said mounting means constraining the fingers to rotate bodily with the stem while providing for lengthwise movement of each finger relative to the stem and to the other fingers;

E. band means encircling the stem and snugly embracing the fingers thereon at a location adjacent to a zone medially of the length of the fingers and providing the sole means to prevent radially outward displacement thereof away from the stem;

F. and friction means maintained effective by said band means to at all times frictionally restrain the fingers against lengthwise motion relative to the stem except in response to the exertion of lengthwise forces upon the fingers that exceed those which are yieldingly imposed upon the tumblers of a cylinder lock by their springs.

References Cited by the Examiner UNITED STATES PATENTS 2,059,376 11/1936 Lombardo 70394 2,070,342 2/1937 Tarrie 70394 3,149,487 9/1964 Martin 70394 PATRICK A. CLIFFORD, Primary Examiner.

ALBERT H. KAMPE, Examiner.

B. R. GAY, Assistant Examiner. 

4. A TOOL FOR PICKING LOCKS OF TH ETYPE WHEREIN THE FRONT PORTION OF A CYLINDER ROTATABLE IN A CASING COOPERATED WITH THE CASING TO DEFINE AN ANNULAR KEYWAY, AND WHEREIN SPRING BIASED TUMBLERS HAVE TUMBLER DRIVERS ARRANGED FOR ACTUATION BY BITTING ON THE END OF A TUBULAR KEY INSERTED INTO THE KEY, SAID PICK COMPRISING: A. AN ELONGATED CYLINDRICAL STEM HAVING (I) A TUBULAR END PORTION OF A SIZE AND SHAPE TO ENTER THE ANNULAR KEYWAY OF A TUBULAR KEY TYPE CYLINDER LOCK AND TO CLOSELY EMBRACE THE FRONT PORTION OF THE CYLINDER, THE WALL OF SAID TUBULAR END PORTION BEING SUBSTANTIALLY THIN SO THAT IT CAN BE INTERPOSED BETWEEN THE TUMBLER DIVERS AND THE CYLINDER, AND (2) A CYLINDER DRIVE LUG ON SAID END PORTION OF THE STEM, PROJECTING FROM THE INTERIOR THEREOF; (B) MEANS ON THE OTHER END PORTION OF THE STEM PROVIDING A HANDLE; (C) TUMBLER ACTUATING MEANS CARRIED BY THE STEM, AT ITS EXTERIOR, COMPRISING A PLURALITY OF SLENDER, ELONGATED FINGERS, ONE OF EACH TUMBLER OF A LOCK TO BE PICKED; D. MEANS MOUNTING SAID FINGERS ON THE STEM, WITH THE FINGERS EXTENDING LENGTHWISE OF THE STEM AND OVER SAID CYLINDER END PORTION THEREOF AND WITH THE FINGERS IN CIRCUMFERENTIALLY SPACED RELATIONSHIP, SAID MOUNTING MEANS CONSTRAINING THE FINGERS TO ROTATE BODILY WITH THE STEM WHILE PROVIDING FOR LENGTH WISE MOVEMENT OF EACH FINGER RELATIVE TO THE STEM AND TO THE OTHER FINGERS; E. BAND MEANS ENCIRCLING THE STEM AND SNUGLY EMBRACING THE FINGERS THEREON AT A LOCATION ADJACENT TO A ZONE MEDIALLY OF THE LENGTH OF THE FINGERS AND PROVIDING THE SOLE MEANS TO PREVENT RADIALLY OUTWARD DISPLACEMENT THEREOF AWAY FROM THE STEM; F. AND FRICTION MEANS MAINTAINED EFFECTIVE BY SAID BAND MEANS TO AT ALL TIMES FRICTIONALLY RESTRAIN THE FINGERS AGAINST LENGTHWISE MOTION RELAIVE TO THE STEM EXCEPT IN RESPONSE TO THE EXERTION OF LENGTHWISE FORCES UPON THE FINGERS THAT EXCEED THOSE WHICH ARE YIELDINGLY IMPOSED UPON THE TUMBLERS OF A CYLINDER LOCK BY THEIR SPRINGS. 